Intramolecular π-stacking in copper(i) diketiminate phenanthroline complexes
Bibliographic record
Abstract
Diketimines N,N'-dibenzyl-2-amino-4-imino-pent-2-ene (1), S,S-N,N'-di(phenylethyl)-2-amino-4-imino-pent-2-ene (2), N,N'-bis(3,4,5-trimethoxyphenylmethyl)-2-amino-4-imino-pent-2-ene (3), N,N'-bis(pentafluorophenylmethyl)-2-amino-4-imino-pent-2-ene (4) and N,N'-diisobutyl-2-amino-4-imino-pent-2-ene (5) react with CuOtBu in the presence of 2,9-R2-1,10-phenanthroline to give the respective neutral, tetracoordinated diketiminate copper(I) phenanthroline complexes 1a+2a (R = H), 1b, 3b-5b (R = Me) and 1c+3c (R = Ph). Crystal structures were obtained for all complexes except 5b and intramolecular π-stacking between the phenanthroline ligand and one or two N-benzyl substituents were observed in 1a, 2a, 1b and 1c, or 3b and 4b, respectively. UV/vis absorption spectra show two transitions in the visible region, a diketiminate-based transition at 373-386 nm and a transition at 600-666 nm, tentatively assigned as an MLCT to phenanthroline. All complexes were weakly luminescent in the solid state at room temperature with lifetimes of less than 60 ns. Weak luminescence was also observed in solution with lambdamax = 720-830 nm for 1b, 1c, 3b, 4b and 5b and short luminescence lifetimes. Intramolecular pi-stacking interactions, which prevent flattening distortions in the solid state, appear to have advantageous effects on luminescence intensities.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".